A better mammogram? Large study that tests 3-D scans

WASHINGTON – A better mammogram? Every time women are asked if they want a 3D mammogram instead of regular radiography, and now US health officials. UU They are beginning a large study to determine whether the choice is newer and, sometimes, more expensive cancer.

It is the last dilemma in a field that already irritates women with contradictory guidelines on when to control: from 40, 45 or 50 years? Annually or every two years?

The problem: Mammograms can save lives if they detect aggressive breast cancers early. But they can also cause damage through frequent false alarms and detect tumors that grow so slowly that they would never have posed a threat, an overdiagnosis that means some women undergo unnecessary treatment.

"But the idea is not so much to find more cancers but to find life-threatening cancers," said Dr. Worta McCaskill-Stevens of the National Cancer Institute, which is funding the new research to determine if the 3 D-scans truly identify the tumors that matter most.

It's one of the largest randomized trials of mammography in decades, and scientists designed the research to do more than answer that key question in 3-D. They hope the findings will also, eventually, help to clear up the confusion surrounding best screening practices.

"The most important thing in this study is that it is moving us to an individualized screening as opposed to what we have now, which is an ideal size for detection," predicted the study's president, Dr. Etta Pisano, radiologist at the Beth Israel Deaconess Medical Center in Boston.

"We will have a better understanding of how to evaluate women so that we do the least amount of harm. "

Who needs a mammogram?

That depends on who you ask." The guidelines vary for women with an average risk of breast cancer . (Those at higher risk, due to family or genetic background, they already receive different advice.)

The American College of Radiology recommends annual mammograms starting at age 40.

The American Cancer Society urges annual controls beginning at age 45 and changing every two years at 55, although it says that women aged 40 to 44 can still opt for a mammogram.

And the US Preventive Services Group, a government advisory group, recommends starting at age 50 With mammograms every two years, it also says that those over 40 can choose an exam earlier.

What about 3-D mammograms?

Standard mammograms take x-rays of both sides of the breast With tomosynthesis, additional x-rays are taken at different angles, not truly three-dimensional, but a computer compiles them into an image similar to 3-D. Approved for the first time by the Food and Drug Administration in 2011, they are still not standard in part due to questions the new study aims to answer.

Some studies have found that tomosynthesis detects more cancer with fewer false alarms; they are often advertised as particularly useful for younger women dense breasts .

How to decide?

Understand that mammograms come with pros and cons, and weigh them, said Dr. Otis Brawley, the chief physician of the American Cancer Society.

Breast cancer is much less common at age 40 than at age 50 or older. After menopause, tumors tend to grow more slowly and women's breast tissue becomes less dense and easier for mammograms to provide a clearer picture.

Consider: for every 1,000 women examined every two years until age 70, starting with 40 instead of 50 preventing additional death, but creating 576 false alarms and 58 unnecessary additional biopsies, the team estimated. In addition, two additional women would be treated for tumors that would never have been life-threatening: that problem of overdiagnosis.

As to which type to choose, some insurers, including Medicare, cover the three-dimensional version and a small number of states oblige coverage. Other insurers may demand that women pay $ 50 to $ 100 more out of pocket. Who finally pays, the additional time to analyze the explorations increases the cost.

The new study

About 100 mammography clinics in the US UU And some in Canada will enroll healthy women ages 45 to 74 who are already planning to get a routine mammogram. They will be randomly assigned to obtain the regular or 3-D version for five years. Most will be examined annually, but postmenopausal women who do not have certain cancer risk factors will be evaluated every two years.

Researchers will track the results of all women, including biopsy samples plus genetic and other tests, and how to rate cancer patients. The lucky database will hopefully help you get more information about which women benefit most from the type and frequency of the tests.

"Mammography has been provocative for many decades, and it is important for women to better understand how mammography is important based on their age and other risk factors," said McCaskill-Stevens.